Knee Pathological Joint Deviations

Question 1

what are the direct / indirect causes of Limited Knee Flexion?

Answer 1

• Hypertonic quads (WA)
• decreased proprioception (WA)
• Forefoot or foot-flat contact w/ increased PF (WA)
• Purposeful to increase limb stability (WA)
• Weak quads (WA) – how to compensate?
• Knee pain (effusion) (WA, SLA)
• Extensor spasticity (ankle PF) (SLA)
• PF contracture (SLA)
• Knee Extension contracture (SLA)
• increased hip flexion or no heel-off in TSt (SLA)
• Impaired motor control knee flexors (SLA)
• Limited thigh advancement 2° increased hamstrings activity(SLA)

Question 2

what are the effects of Limited Knee Flexion?

Answer 2

• increased passive dorsiflexion
• increased energy cost
• interferes with foot clearance –> toe drag
• seen in pass-retract

Question 3

what are substitutions for Weak Quads?

Answer 3

• pass retract motion will extend knee at terminal swing
• hip extension / early PF limit tibial advancement and quad strain in LR
• hyperextension of knee thru stance via anterior BW vector
• extensor thrust

Question 4

what are the effects of Knee Extensor Thrust?

Answer 4

• Decreases forward progression of tibia (WA, SLS)
• Decreased normal shock absorbing flexion (WA)
• Potential injury to posterior knee capsule (WA, SLS)
• Provides stability (WA, SLS)

Question 5

what are the direct / indirect causes of Excessive Knee Flexion?

Answer 5

• Knee flexion contracture or hypertonicity (of which muscles?)
• Weak quads (ecc control)
• Knee pain
• Mass flexion - synergy
• increased PF ROM – Stance
• increased dorsiflexion ROM - Stance
• Inability to extend knee while maintaining flexed hip - Swing
• Purposeful to lower opposite limb (TSt) for forefoot or foot-flat IC - Stance
• PPT w/ hip flexion contracture - Swing
• increased contralateral stance stability
• increased hip flexion ROM - Swing

Question 6

what are the effects of Excessive Knee Flexion?

Answer 6

• increases demand on the plantarflexors, quadriceps, and hip extensors
• decreased body advancement @ thigh
• decreases limb stability
• increased dorsiflexion
• decreased step length

Question 7

what are the effects of Excessive Knee Flexion in SWING?

Answer 7

• decreased step length of reference limb
• interferes with heel first IC
• allows clearance of PF’d foot

Question 8

what are the causes / effects of Varus/Valgus Angulation?

Answer 8

Causes:
- Joint or ligamentous instability, congenital, developmental or traumatic bony deformity
- Dysfunctional subtalar joint

Effects:
- decreases limb stability
- May require proximal or distal compensation
- May result in knee pain
- May increase or decrease BOS

Question 9

what are the causes / effects of Wobble Knee?

Answer 9

Small alternations of knee flexion/extension

Causes:
- decreased proprioception
- increased quads or PF activity – spastic clonus

Effects:
- decreases forward momentum
- decreases limb stability & balance